The present invention relates to a toner production method and a toner production apparatus.
Heretofore, has been useful as a toner constituting an electrostatic image developing agent, a so-called coalescence toner, which is produced employing an emulsion coalescence method (refer, for example, to Patent Document 1 or Patent Document 2).
Coalescence toners exhibit excellent characteristics in which the particle size distribution is narrow and the shape of toner particles is uniform. Further, due to its production processes, it is possible to control the shape of toner particles within a wide range, namely from a sphere to irregular shapes. Consequently, since excellent electrification properties, transferability, and cleaning properties are achieved, it is possible to apply the above toner to a high speed image forming apparatus.
However, in regard to the coalescence toner, it is somewhat problematic to produce one exhibiting the desired particle size distribution and shape at high accuracy during its mass production. In order to overcome the above drawbacks, various techniques are known (refer, for example, to Patent Document 3). However, sufficient desired effects have not been attained even employing these techniques.
Specifically, when employed as a non-magnetic single component developer, toner particles, the shape of which approaches a sphere, enables static electrification to be higher. However, the range of the allowed particle shape is markedly narrowed due to the relationship of conveying properties to the development region and cleaning properties.
On the other hand, developed have been technologies to produce toner capable of appropriately being employed as a low temperature fixed toner employing an emulsion coalescence method. In order to provide the resulting coalescence toner with characteristics suitable for a low temperature fixed toner, when, as toner materials, toner resins at a softening point of 100° C. or less, as well as releasing agents and fixing aids at a melting point of 80° C. or less are employed, the variation range of the shape of toner particles, in the process to control the shape of toner particles, is broadened. Namely, as particles become sensitive, problems occur in which it is difficult to control the shape of toner particles resulting in high accuracy.
Further, in the production processes of the coalescence toner, commonly employed as a reaction apparatus is a so-called reaction vessel which is structured in such a manner that, for example, a heat-exchange jacket is arranged on the outer periphery as well as in the interior, stirring blades are arranged. In the production method employing the above reaction vessel, problems occur in which the cycle to heat and cool the reaction vessel results in large energy loss and thereby low heating and cooling efficiency.
In addition, demanded is a production method which retards discharge of carbon dioxide gas while enhancing productivity.
(Patent Document 1) Japanese Patent Publication for Public Inspection (hereinafter referred to as JP-A) No. 2000-214629
(Patent Document 2) JP-A No. 2000-250263
(Patent Document 3) JP-A No. 2001-5219